1. Field of the Invention
The present invention relates to a vehicle lamp and, more particularly, to a vehicle lamp with a heat sink.
2. Description of the Prior Arts
Light-emitting diodes (LED) are often used as illuminants in vehicles because of their energy saving property, high efficiency of illumination and small volume. A portion of power inputted into an LED is transformed into heat. To achieve improved brightness, multiple LEDs may be disposed in an array, and technologies focus on attaining a high number to area ratio. However, increased numbers of LEDs per surface area concentrate heat produced and, therefore, requires a cooling system. Conventionally, an LED array is disposed on a heat sink.
With reference to FIG. 5, a conventional lamp comprises a bracket (90), a lens (92), an LED array (93) and a heat sink (96). The bracket (90) has a front, a rear, a chamber and at least one throughhole (91). The chamber is formed between the front and the rear of the bracket (90). The at least one throughhole (91) is formed through the rear of the bracket (90) and communicates with the chamber. The lens (92) is mounted over the chamber, at the front of the bracket (90). The LED array (93) is mounted inside the chamber of the bracket (90) and has a circuit board (94) and multiple LEDs (95). The circuit board (94) is selectively electrically connected to a power source and has a front side and a rear side. The LEDs (95) are mounted on the front side of the circuit board (94). The heat sink (96) is mounted on the rear side of the circuit board (94) and has multiple cooling fins (98). The cooling fins (98) respectively extend through the at least one throughhole (91) of the bracket (90). Thus, by increasing a surface area of the circuit board (94), the cooling fins (98) can facilitate heat dissipating efficiency of the vehicle lamp.
However, dust from the environment can easily pass through the at least one throughhole (91) to enter the chamber and may also accumulate on the LED array (93) and affect illumination of the LEDs (95). Further, the dust may cover the cooling fins (98) and insulate the cooling fins (98) thereby preventing radiation of heat and possibly causing overheating causing damage or even terminal failure to the LED array (93).
To overcome the shortcomings, the present invention provides a vehicle lamp to mitigate or obviate the aforementioned problems.